A nationwide survey to assess the prevalence of dental caries throughout the United States was designed and implemented during the 1979-80 school year. A probability sample of school-aged children in grades kindergarten through twelve was selected for examination for dental caries, gingivitis, and need for restorative treatment. Estimates of disease level and treatment need were made for the continental U.S. and each of seven geographic regions by age, race and sex. Additional anslyses such as patterns of eruption, caries susceptibility by surface type and caries prevalence by residential fluoride history were calculated.